AuthorizationIdentifier

User names within the Derby system
are known as authorization identifiers. The authorization identifier
represents the name of the user, if one has been provided in the connection
request. The default schema for a user is equal to its authorization identifier.
User names can be case-sensitive within the authentication system, but they
are always case-insensitive within Derby's
authorization system unless they are delimited. For more information, see
the Derby Developer's Guide.